The present invention relates to a control system for an engine system equipped with intake and exhaust valves operated by electromagnetic actuators, and more particularly to a control system which is arranged to adaptively control an engine system when one of intake and exhaust valves is put in an abnormal condition.
Japanese Patent Provisional Publication No. 8-200135 discloses a control system of an engine system with electromagnetically operated intake and exhaust valves. This engine system is arranged to stop a fuel injection and to close at least one of intake and exhaust valves when an abnormal operation of one of the valves is detected.
However, even if an abnormality of a valve is detected after the fuel injection by the conventional control system, a combustion stroke is once executed at a cylinder having the abnormal valve before stopping the fuel injection. This may degrade the parts in an intake passage or exhaust passage.
It is an object of the present invention to provide an engine control system which is capable of suppressing the degradation of parts for an engine even if electromagnetically operated intake and exhaust valves are put in an abnormal condition.
An engine control system according to the present invention is for an engine system which comprises electromagnetically operated intake and exhaust valves, a spark plug, a primary ignition coil, a secondary ignition coil generating an induction voltage according to current-flowing and current-stopping operations to the primary ignition coil, the secondary ignition coil outputting the induction voltage to the spark plug. The engine control system comprises a control unit which is arranged to decide whether each of intake and exhaust valves is put in an abnormal condition, to close a normal valve of the intake and exhaust valves when one of the intake and exhaust valves is put in the abnormal condition, and to stop the current-flowing of the primary ignition coil when one of the intake and exhaust valves is put in the abnormal condition and when the primary ignition coil does not start the current-flowing.